Allelic variation and genetic diversity of HMW glutenin subunits in Chinese wheat (Triticum aestivum L.) landraces and commercial cultivars.

Wheat landraces have abundant genetic variation at the Glu-1 loci, which is desirable germplasms for genetic enhancement of modern wheat varieties, especially for quality improvement. In the current study, we analyzed the allelic variations of the Glu-1 loci of 597 landraces and 926 commercial wheat varieties from the four major wheat-growing regions in China using SDS-PAGE. As results, alleles Null, 7+8, and 2+12 were the dominant HMW-GSs in wheat landraces. Compared to landraces, the commercial varieties contain higher frequencies of high-quality alleles, including 1, 7+9, 14+15 and 5+10. The genetic diversity of the four commercial wheat populations (alleles per locus (A) = 7.33, percent polymorphic loci (P) = 1.00, effective number of alleles per locus (Ae) = 2.347 and expected heterozygosity (He) = 0.563) was significantly higher than that of the landraces population, with the highest genetic diversity found in the Southwestern Winter Wheat Region population. The genetic diversity of HMW-GS is mainly present within the landraces and commercial wheat populations instead of between populations. The landraces were rich in rare subunits or alleles may provide germplasm resources for improving the quality of modern wheat.

Improvement in gastrointestinal bleeding after septal myectomy for hypertrophic cardiomyopathy.

OBJECTIVE: Patients with obstructive hypertrophic cardiomyopathy may have occult gastrointestinal bleeding. In this study, we analyzed outcomes of septal myectomy in patients who had a history of gastrointestinal bleeding preoperatively to understand patient characteristics and impact of septal reduction on recurrent gastrointestinal bleeding. METHODS: We analyzed 73 adult patients who had a history of gastrointestinal bleeding before transaortic septal myectomy for obstructive hypertrophic cardiomyopathy and compared outcomes to 219 patients without gastrointestinal bleeding preoperatively. RESULTS: Patients with preoperative history of gastrointestinal bleeding were older (median (IQR) age, 65 (59-69) years, P < .001) and were more likely to have systemic hypertension (70% vs 53%, P = .020) and coronary artery disease (25% vs 13%, P = .026). Preoperatively, patients with gastrointestinal bleeding had a larger left atrial volume index (median, 53 mL/m2; interquartile range, 42-67; P = .006) and greater right ventricular systolic pressure (median, 36 mm Hg; interquartile range, 32-49; mm Hg, P = .005) but no significant difference in severity of outflow tract obstruction (P = .368). There were no perioperative deaths. The estimated 5- and 10-year survivals were 96.6% and 81.8%, respectively. At a median of 3.4 (interquartile range, 1.9-9.1) years after septal myectomy, 11 patients (15%) had recurrence of gastrointestinal bleeding, which was attributed to angiodysplasia or unknown causes in 6 patients (8%). CONCLUSIONS: Patients with a preoperative history of gastrointestinal bleeding have favorable short- and long-term outcomes after septal myectomy for obstructive hypertrophic cardiomyopathy. Remission of gastrointestinal bleeding was observed in 85% of patients postprocedure, and only 8% of the patients had recurrent gastrointestinal bleeding due to angiodysplasia or unknown causes.

Association of left atrial function with frailty: The Atherosclerosis Risk in Communities (ARIC) study.

BACKGROUND: Frailty is common in people with cardiovascular disease. Worse left atrial (LA) function is an independent risk factor for cardiovascular disease. However, whether worse LA function is associated with frailty is unclear. METHODS: We included 3292 older adults from the Atherosclerosis Risk in Communities study who were non-frail at baseline (visit 5, 2011-2013) and had LA function (reservoir, conduit, and contractile strain) measured from two-dimensional speckle-tracking echocardiography. LA stiffness index was calculated as a ratio of E/e' to LA reservoir strain. Frailty was defined using the validated Fried frailty phenotype. Incident frailty was assessed between 2016 and 2019 during two follow-up visits. LA function was analyzed as quintiles. Multivariable logistic regression examined odds of incident frailty. RESULTS: Median (interquartile range [IQR]) age was 74 (71-77) years, 58% were female, and 214 (7%) participants developed frailty during a median (IQR) follow-up of 6.3 (5.6-6.8) years. After adjusting for baseline confounders and incident cardiovascular events during follow-up, the odds of developing frailty was 2.42 (1.26-4.66) times greater among participants in the lowest (vs highest) quintile of LA reservoir strain and 2.41 (1.11-5.22) times greater among those in the highest (vs lowest) quintile of LA stiffness index. Worse LA function was significantly associated with the development of exhaustion, but not the other components of the Fried frailty phenotype. CONCLUSIONS: Worse LA function is associated with higher incidence of frailty and exhaustion component independent of LA size and left ventricular function. Future studies are needed to elucidate the underlying mechanisms that drive the observed association.

Mechanical or biological prosthesis for aortic valve replacement in patients aged 45 to 74 years.

OBJECTIVE: The selection of valve prostheses for patients undergoing surgical aortic valve replacement remains controversial. In this study, we compared the long-term outcomes of patients undergoing aortic valve replacement with biological or mechanical aortic valve prostheses. METHODS: We evaluated late results among 5762 patients aged 45 to 74 years who underwent biological or mechanical aortic valve replacement with or without concomitant coronary artery bypass from 1989 to 2019 at 4 medical centers. The Cox proportional hazards model was used to compare late survival; the age-dependent effect of prosthesis type on long-term survival was evaluated by an interaction term between age and prosthesis type. Incidences of stroke, major bleeding, and reoperation on the aortic valve after the index procedure were compared between prosthesis groups. RESULTS: Overall, 61% (n = 3508) of patients received a bioprosthesis. The 30-day mortality rate was 1.7% (n = 58) in the bioprosthesis group and 1.5% (n = 34) in the mechanical group (P = .75). During a mean follow-up of 9.0 years, the adjusted risk of mortality was higher in the bioprosthesis group (hazard ratio, 1.30, P < .001). The long-term survival benefit associated with mechanical prosthesis persisted until 70 years of age. Bioprosthesis (vs mechanical prosthesis) was associated with a similar risk of stroke (P = .20), lower risk of major bleeding (P < .001), and higher risk of reoperation (P < .001). CONCLUSIONS: Compared with bioprostheses, mechanical aortic valves are associated with a lower adjusted risk of long-term mortality in patients aged 70 years or less. Patients aged less than 70 years undergoing surgical aortic valve replacement should be informed of the potential survival benefit of mechanical valve substitutes.

SNP-revealed genetic diversity in wild emmer wheat correlates with ecological factors.

BACKGROUND: Patterns of genetic diversity between and within natural plant populations and their driving forces are of great interest in evolutionary biology. However, few studies have been performed on the genetic structure and population divergence in wild emmer wheat using a large number of EST-related single nucleotide polymorphism (SNP) markers. RESULTS: In the present study, twenty-five natural wild emmer wheat populations representing a wide range of ecological conditions in Israel and Turkey were used. Genetic diversity and genetic structure were investigated using over 1,000 SNP markers. A moderate level of genetic diversity was detected due to the biallelic property of SNP markers. Clustering based on Bayesian model showed that grouping pattern is related to the geographical distribution of the wild emmer wheat. However, genetic differentiation between populations was not necessarily dependent on the geographical distances. A total of 33 outlier loci under positive selection were identified using a FST-outlier method. Significant correlations between loci and ecogeographical factors were observed. CONCLUSIONS: Natural selection appears to play a major role in generating adaptive structures in wild emmer wheat. SNP markers are appropriate for detecting selectively-channeled adaptive genetic diversity in natural populations of wild emmer wheat. This adaptive genetic diversity is significantly associated with ecological factors.

Genetic diversity revealed by single nucleotide polymorphism markers in a worldwide germplasm collection of durum wheat.

Evaluation of genetic diversity and genetic structure in crops has important implications for plant breeding programs and the conservation of genetic resources. Newly developed single nucleotide polymorphism (SNP) markers are effective in detecting genetic diversity. In the present study, a worldwide durum wheat collection consisting of 150 accessions was used. Genetic diversity and genetic structure were investigated using 946 polymorphic SNP markers covering the whole genome of tetraploid wheat. Genetic structure was greatly impacted by multiple factors, such as environmental conditions, breeding methods reflected by release periods of varieties, and gene flows via human activities. A loss of genetic diversity was observed from landraces and old cultivars to the modern cultivars released during periods of the Early Green Revolution, but an increase in cultivars released during the Post Green Revolution. Furthermore, a comparative analysis of genetic diversity among the 10 mega ecogeographical regions indicated that South America, North America, and Europe possessed the richest genetic variability, while the Middle East showed moderate levels of genetic diversity.

Outcomes of concomitant myectomy and left ventricular apical aneurysm repair in patients with hypertrophic cardiomyopathy.

OBJECTIVES: Hypertrophic cardiomyopathy with left ventricular apical aneurysm is a phenotype associated with a 4-fold increase in the risk for sudden cardiac death. In this study, we describe the surgical outcome of concomitant apical aneurysm repair in patients undergoing transapical myectomy for hypertrophic cardiomyopathy. METHODS: We identified 67 patients with left ventricular apical aneurysms who underwent transapical myectomy and apical aneurysm repair between July 2000 and August 2020. Long-term survival was compared with that of 2746 consecutive patients undergoing transaortic septal myectomy for obstructive hypertrophic cardiomyopathy with subaortic obstruction. RESULTS: Transapical myectomy was indicated for midventricular obstruction (n = 44) or left ventricular remodeling for diastolic heart failure (n = 29). Preoperatively, 74.6% (n = 50) of patients were in New York Heart Association class III/IV heart failure, and 34.3% (n = 23) of patients had experienced syncope or presyncope. Atrial fibrillation was documented in 22 patients (32.8%), and episodes of ventricular arrhythmias were recorded in 30 patients (44.8%). Thrombus was present in the apical aneurysm in 6 patients. During a median (interquartile range) follow-up of 4.9 (1.8-7.6) years, the estimated 1- and 5-year survivals were 98.5% and 94.5%, respectively, which were not significantly different from that of patients undergoing transaortic septal myectomy for obstructive hypertrophic cardiomyopathy (P = .52) or an age- and sex-matched US general population (P = .40). CONCLUSIONS: Apical aneurysm repair in conjunction with septal myectomy is a safe procedure, and the good long-term survival of patients suggests that the procedure may reduce cardiac-related death in this high-risk hypertrophic cardiomyopathy population.

In-Hospital Outcomes of Acute Ischemic Stroke in Patients With Hypertrophic Cardiomyopathy.

Objective: To investigate the in-hospital outcomes of acute ischemic stroke in patients with hypertrophic cardiomyopathy (HCM). Patients and Methods: Using weighted discharge data from the National Inpatient Sample, we identified 5804 nonelective hospitalizations for ischemic stroke in adult patients with HCM between 2011 and 2017. For comparison, 58,179 hospitalizations for ischemic stroke in adult patients without HCM were selected as controls using the simple random sampling method. Results: Compared with the patients without HCM, those with HCM had a higher prevalence of hyperlipidemia (62.4% vs 57.5%, respectively, P<.001) and chronic heart failure (25.4% vs 13.6%, respectively, P<.001) but a lower prevalence of diabetes (28.2% vs 34.9%, respectively, P<.001) and hypertension (42.9% vs 53.4%, respectively, P<.001). Atrial fibrillation was documented in 45.1% (n=2617) of the patients with HCM. However, only 28.0% (n=733) of these patients had long-term use of anticoagulants. The in-hospital death rate among the patients with HCM was 6.3% (n=368), which was significantly higher than that in the patients without HCM (4.1%, P<.001). Having HCM (odds ratio [OR], 1.35; P<.001), atrial fibrillation (OR, 2.08; P<.001), and chronic heart failure (OR, 1.65; P<.001) were significant predictors of in-hospital death. In patients with HCM who were discharged alive, 50.0% were transferred to skilled nursing facilities compared with 45.3% of those without HCM (P<.001). Conclusion: The prognosis of acute ischemic stroke is worse in patients with HCM than in those without HCM. These findings emphasize the importance of aggressive treatment of predisposing factors for stroke in patients with HCM, especially atrial fibrillation.

Genomic landscape of 891 RET fusions detected across diverse solid tumor types.

In this study, we report the clinicopathologic and genomic profiles of 891 patients with RET fusion driven advanced solid tumors. All patient samples were tested using a tissue-based DNA hybrid capture next generation sequencing (NGS) assay and a subset of the samples were liquid biopsies tested using a liquid-based hybrid capture NGS assay. RET fusions were found in 523 patients with NSCLC and in 368 patients with other solid tumors. The two tumor types with the highest number of RET fusion were lung adenocarcinoma and thyroid papillary carcinoma, and they had a prevalence rate 1.14% (455/39,922) and 9.09% (109/1199), respectively. A total of 61 novel fusions were discovered in this pan-tumor cohort. The concordance of RET fusion detection across tumor types among tissue and liquid-based NGS was 100% (8/8) in patients with greater than 1% composite tumor fraction (cTF). Herein, we present the clinicopathologic and genomic landscape of a large cohort of RET fusion positive tumors and we observed that liquid biopsy-based NGS is highly sensitive for RET fusions at cTF ≥1%.

Transcriptome and Metabolite Insights into Domestication Process of Cultivated Barley in China.

The domestication process of cultivated barley in China remains under debate because of the controversial origins of barley. Here, we analyzed transcriptomic and non-targeted metabolic data from 29 accessions together with public resequencing data from 124 accessions to explore the domestication process of cultivated barley in China (Cb-C). These analyses revealed that both Cb-C and Tibetan wild barley (Wb-T) were the descendants of wild barley from the Near East Fertile Crescent (Wb-NE), yielding little support for a local origin of Wb-T. Wb-T was more likely an intermediate in the domestication process from Wb-NE to Cb-C. Wb-T contributed more genetically to Cb-C than Wb-NE, and was domesticated into Cb-C about 3300 years ago. These results together seem to support that Wb-T may be a feralized or hybrid form of cultivated barley from the Near East Fertile Crescent or central Asia. Additionally, the metabolite analysis revealed divergent metabolites of alkaloids and phenylpropanoids and these metabolites were specifically targeted for selection in the evolutionary stages from Wb-NE to Wb-T and from Wb-T to Cb-C. The key missense SNPs in the genes HORVU6Hr1G027650 and HORVU4Hr1G072150 might be responsible for the divergence of metabolites of alkaloids and phenylpropanoids during domestication. Our findings allow for a better understanding of the domestication process of cultivated barley in China.

Safety of Bariatric Surgery in Obese Patients With Hypertrophic Cardiomyopathy.

Obesity is an independent risk factor for heart failure in patients with hypertrophic cardiomyopathy (HC). In this study, we examined national trends and early outcomes of bariatric surgery for obesity in patients with HC. Using the weighted discharge data from the National Inpatient Sample, we identified adult patients with HC who underwent elective bariatric surgery for obesity between 2011 and 2017. A total of 443 obese patients with HC were identified, and 42% (n = 185) had obstructive HC. The annual number of patients increased from 18 in 2011 to 130 in 2017. Overall, the median (interquartile range) age was 50 (43 to 57) years, and 85 patients (19%) were 60 years or older. Approximately 20% (n = 90) of the patients had heart failure at the time of operation. Atrial fibrillation was present in 83 patients (19%), and 22% (n = 95) of the cohort had a pacemaker or automatic cardiac defibrillator implanted before the operation. Laparoscopic sleeve gastrectomy (72%, n = 318) and laparoscopic Roux-en-Y gastric bypass (25%, n = 110) were the most commonly performed bariatric procedures. Overall, patients stayed in the hospital for a median (interquartile range) of 2 (1 to 2) days. During the hospital stay, there were no deaths, myocardial infarctions, or documented episodes of thromboembolism. In conclusion, bariatric surgery in patients with HC is performed more frequently in recent years and is safe and associated with few perioperative complications. Because of the impact of obesity on long-term survival, clinicians should strongly consider bariatric surgery for obese HC patients who do not respond to conservative weight loss measures.

Assessment of soil quality for guided fertilization in 7 barley agro-ecological areas of China.

Soil quality is the basis for the development of sustainable agriculture and may be used for evaluating the sustainability of soil management practices. Soil quality status and integrated soil quality index (SQI) in sampled 97 farmlands distributed in 7 barley agro-ecological areas of China were analyzed by using 13 soil chemical parameters. The results showed six principal components totally explained 72% variability for the 13 parameters and identified 9 parameters (includes pH, NH4+-N, NO3--N, available P, available K, exchangeable Mg, DTPA-Fe, DTPA-Cu and Cl-) with high factor loading values as the minimum data set (MDS) for assessing soil quality. Average soil quality of all farmlands is moderate (SQI = 0.62). The SQI of barley farmlands in 7 agro-ecological areas showed the following order: Inner Mongolia Plateau (0.75 ± 0.02) > Yunnan-Kweichow Plateau (0.72 ± 0.06) > Qinghai-Tibet Plateau (0.63 ± 0.08) > Yangtze Plain (0.62 ± 0.10) > Huanghuai Region (0.58 ± 0.09) > Northeast China Plain (0.56 ± 0.07) > Xinjiang Province (0.54 ± 0.07). Total 29 out of 97 farmlands in 7 areas have low SQI level (< 0.55). Hence, these farmlands require urgent attention for soil quality improvement through modification of the soil parameters in the MDS.

Posterior Wall Thickness Associates With Survival Following Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy.

BACKGROUND: The left ventricular (LV) posterior wall thickness (PWT) is a predictor of sudden cardiac death in pediatric patients with hypertrophic cardiomyopathy (HCM), but the prognostic importance of PWT in adults has not been examined. OBJECTIVES: The goal of this study was to evaluate the association of LV PWT with late survival in adult patients undergoing septal myectomy for obstructive HCM. METHODS: This single-center study reviewed 2,418 patients who underwent transaortic septal myectomy for obstructive HCM. RESULTS: The median preoperative PWT was 13 (IQR: 11-15) mm. Patients with PWT >13 mm tended to have systemic hypertension (55.4% vs 49.1%; P = 0.002) and a larger body mass index (median: 30.8 [IQR: 27.1-35.1] kg/m2 vs 29.6 [IQR: 26.1-33.9] kg/m2; P < 0.001). Preoperatively, PWT >13 mm was associated with increased septal thickness (median: 21 [IQR: 18-24] mm vs 19 [IQR: 17-22] mm; P < 0.001), greater maximum instantaneous left ventricular outflow tract (LVOT) gradient at rest (median: 67 [IQR: 36-96] mm Hg vs 47 [IQR: 19-79] mm Hg), and increased likelihood of moderate or greater mitral valve regurgitation (54.3% vs 47.3%; P = 0.001). However, PWT was not related to the severity of limitations measured by New York Heart Association functional class (P = 0.674). After adjusting for baseline covariates, greater PWT was an independent risk factor for late mortality after septal myectomy (P = 0.003). CONCLUSIONS: PWT is a newly identified predictor of reduced long-term survival after septal myectomy that is independent of septal thickness and severity of LVOT gradient. Future studies are warranted to investigate the mechanisms underlying the association and the potential usefulness of PWT in patient management.

Association of Preoperative Sleep-Disordered Breathing With Functional Status After Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy.

Background: Sleep-disordered breathing (SDB) is a risk factor for heart failure symptoms in patients with hypertrophic cardiomyopathy (HCM). However, the relationship between preoperative SDB and postoperative functional status after septal myectomy (SM) is unknown. In this study, we investigated the association of preoperative SDB with late self-reported health status among patients undergoing SM for obstructive HCM. Methods: Prior to SM, an overnight pulse oximetry test was used to measure oxygen desaturation index (ODI), which indicates the average number of desaturation episodes with at least 4% of drops in oxygen level from baseline per hour of sleep. Patients reported postoperative function through a questionnaire-based survey completed 3-5 years following SM. Results: We analyzed 264 patients who underwent transaortic SM from November 2005 through April 2016. On predischarge transthoracic echocardiography post-procedure, no significant difference was present in the extent of mitral valve regurgitation (P = 0.524), left ventricular outflow tract gradient (P = 0.405), or septal thickness (P = 0.744) related to ODI. At 3 to 5 years after their operation, 236 patients (89%) reported good or excellent health. Approximately 18% (n = 48) and 8% (n = 22) of the cohort continued to experience exertional dyspnea and chest tightness, respectively, on walking 2 blocks or less. A greater ODI was not an independent predictor of worse health status or residual symptoms. Conclusions: Relief of left ventricular outflow tract obstruction in patients with obstructive HCM improves symptoms, with 89% of patients reporting good or excellent health. Preoperative SDB is not significantly associated with late functional status after septal myectomy.

Contexte: Les troubles respiratoires du sommeil (TRS) sont un facteur de risque d'insuffisance cardiaque chez les patients atteints de cardiomyopathie hypertrophique (CMH). Toutefois, la relation entre la présence préopératoire d'un TRS et le statut fonctionnel postopératoire après une myectomie septale (MS) est inconnue. Dans notre étude, nous avons examiné l'association entre les TRS préopératoires et le statut de santé à long terme, tel qu'autodéclaré par les patients ayant subi une MS dans le traitement de la CMH. Méthodologie: Un test nocturne d'oxymétrie de pouls, réalisé avant la MS, a été utilisé pour déterminer l'indice de désaturation en oxygène (IDO), qui indique le nombre moyen d'épisodes de désaturation avec une baisse d'oxygène d'au moins 4 % sous le niveau de base, par heure de sommeil. Les patients ont rapporté leur fonction postopératoire au moyen d'un sondage sous forme de questionnaire, rempli de 3 à 5 ans après la MS. Résultats: Les données de 264 patients ayant subi une MS transaortique entre novembre 2005 et avril 2016 ont été analysées. À l'échocardiographie transthoracique postopératoire réalisée avant le congé hospitalier, aucune différence significative liée à l'IDO n'a été notée quant à l'insuffisance de la valve mitrale (p = 0,524), au gradient de la voie d'éjection du ventricule gauche (p = 0,405), ou à l'épaisseur du septum (p = 0,744) des patients. Trois à cinq ans après l'intervention chirurgicale, 236 patients (89 %) ont rapporté être en bonne ou en excellente santé. Environ 18 % (n = 48) et 8 % (n = 22) des patients de la cohorte présentaient encore une dyspnée à l'effort et une oppression thoracique, respectivement, après une marche de deux coins de rue ou moins. Un IDO plus élevé ne constituait pas un facteur prédictif indépendant pour un état de santé plus défavorable ou pour la présence de symptômes résiduels. Conclusions: Le traitement d'une obstruction du sang par le ventricule gauche chez les patients présentant une CMH obstructive permet d'améliorer leurs symptômes, et 89 % des patients rapportent par la suite être en bonne ou en excellente santé. Les TRS préopératoires ne sont pas associés de manière significative au statut fonctionnel postopératoire après une myectomie septale.

Cardiopulmonary exercise test in patients with obstructive hypertrophic cardiomyopathy.

OBJECTIVE: The study objective was to analyze performance on cardiopulmonary exercise testing and its prognostic value in patients with obstructive hypertrophic cardiomyopathy undergoing septal myectomy. METHODS: We reviewed patients with obstructive hypertrophic cardiomyopathy who had cardiopulmonary exercise testing before septal myectomy from 2005 to 2016. Causes of functional impairment and their impact on survival were analyzed. RESULTS: A total of 752 patients had cardiopulmonary exercise testing at a median of 16 days (interquartile range, 2-56) before myectomy. The median exercise time was 6.6 (5.3-8.0) minutes. Functional aerobic capacity was 64% (53%-75%) of predicted, and metabolic equivalent of task was 5.2 (4.1-6.4). The peak oxygen consumption was 18.0 (14.2-21.9) mL/kg/min, which was 60% (49%-72%) of the predicted value. The primary causes for low peak oxygen consumption were impaired cardiac output (73.7%), limited heart rate reserve (52.0%), and obesity (48.2%). Resting outflow tract gradient correlated poorly to peak oxygen consumption, but the use of beta-blockers was associated with reduced peak oxygen consumption. During a median (interquartile range) of 9.0 (6.8-11.7) years of follow-up, the estimated 5- and 10-year survivals were 97% and 91%, respectively. Greater adjusted peak oxygen consumption (hazard ratio, 0.98; P = .011) and abnormal pulse oxygen increase (hazard ratio, 0.44; P = .003) were independently associated with better long-term survival after myectomy. CONCLUSIONS: Among patients with hypertrophic cardiomyopathy undergoing septal myectomy, functional capacity is severely impaired despite receiving optimal medical treatment. We identified risk factors of reduced long-term survival from preoperative cardiopulmonary exercise testing that may aid risk stratification in patients undergoing septal myectomy.

Transapical Ventricular Remodeling for Hypertrophic Cardiomyopathy With Systolic Cavity Obliteration.

BACKGROUND: Some patients with hypertrophic cardiomyopathy (HCM) present with reduced left ventricular (LV) stroke volume and elongated systolic cavity obliteration due to symmetric LV hypertrophy. In this report, we detail our experience with transapical septal myectomy to enlarge the LV volume and to relieve cavity obliteration in this unique subgroup of patients with HCM. METHODS: We analyzed 38 patients with HCM who had extended symmetric LV hypertrophy and underwent transapical septal myectomy to enlarge the LV cavity from February 2001 to May 2021. RESULTS: At the time of evaluation for operation, 84.2% (n = 32) of the patients were in New York Heart Association class III/IV. The peak oxygen consumption was 51.5% (44.0%-58.0%) of the normal predicted values on the preoperative exercise stress test (n = 16). Preoperative left atrial sizes in this cohort were enlarged (left atrial volume index, 39.0 [33.5-51.5] mL/m2), despite only 4 patients with moderate or greater mitral valve regurgitation. All patients underwent transapical septal myectomy to enlarge the LV cavity size. There was no postoperative (within 30 days) death. During a median (interquartile range) follow-up of 3.4 (0.7-6.9) years, the estimated survival rates were 100%, 92%, and 87% at 1, 3, and 5 years, respectively. Follow-up surveys suggested that 16 of the 17 contacted patients experienced improvement in their heart function after the procedure. CONCLUSIONS: Transapical myectomy to enlarge LV cavity volume can be performed safely with good early survival and functional results. This procedure is an important alternative to cardiac transplantation for HCM patients with systolic cavity obliteration and progressive heart failure.

Patient-Reported Atrial Fibrillation After Septal Myectomy for Hypertrophic Cardiomyopathy.

BACKGROUND: Patient-reported outcomes are important metrics of medical and surgical care. In this study, we investigated the prevalence and risk factors of patient-reported postdischarge atrial fibrillation (AF) after septal myectomy for obstructive hypertrophic cardiomyopathy. METHODS: Patients undergoing transaortic septal myectomy from August 2001 to January 2017 were contacted regarding postdischarge AF through questionnaire-based surveys sent at 3, 5, and 10 years post procedure. For each patient, the most recent survey response was analyzed. RESULTS: Among 949 patients, 248 (26.1%) last responded at 3 years post procedure, 353 (37.2%) at 5 years, and 348 (36.7%) at 10 years. The overall incidence of patient-reported postdischarge AF was 34.4% (n = 326), and at 3, 5, and 10 years, the incidences were 22.2%, 34.8%, and 42.5% (P < .001). After multivariable adjustment, history of preoperative AF (odds ratio [OR] 5.566, P < .001), early postoperative AF within the first 30 days (OR 2.211, P < .001), preoperative left atrial volume index (OR 1.014, P = .005), postoperative right ventricular systolic pressure (OR 1.021, P = .013), postoperative moderate or greater mitral valve regurgitation (OR 1.893, P = .022), and preoperative septal thickness (OR 1.043, P = .036) were independently associated with patient-reported postdischarge AF. CONCLUSIONS: The incidence of patient-reported postdischarge AF increases with increasing length of follow-up after septal myectomy. We identified several risk factors for late postdischarge AF that were associated with chronicity of left ventricular outflow tract obstruction, and earlier intervention may mitigate late atrial arrhythmias.

Impact of Body Mass Index on Outcome of Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy.

BACKGROUND: Obesity is highly prevalent in patients with obstructive hypertrophic cardiomyopathy (HCM). In this study, we investigated the impact of body mass index (BMI) in patients undergoing septal myectomy (SM) for obstructive HCM. METHODS: We reviewed 2746 patients who underwent transaortic SM for obstructive HCM from February 1993 through September 2018. Patients were stratified into 3 groups based on BMI (normal weight, <25 kg/m2; overweight, 25 to <30 kg/m2; and obese, ≥30 kg/m2). RESULTS: Preoperatively, the median left ventricular outflow tract gradient was 58 mm Hg, and there was no difference in gradients across BMI strata (P = .35). The percentage of obese patients with moderate or greater mitral valve regurgitation was lower (45.8%) compared with normal weight (52.9%) and overweight (55.4%) patients (P < .001). However, patients with a higher BMI were more likely to have New York Heart Association Functional Classification III/IV limitation at presentation (P < .001). After myectomy, anteroseptal thickness (P = .115) and left ventricular outflow tract gradient (P = .210) did not differ between groups. There were 14 (0.5%) deaths within 30 days postoperatively, and the risk was similar across BMI strata (P = .448). Model-estimated changes in average BMI at 10 years postprocedure showed stratum-specific increases ranging from 0.60 to 1.56 kg/m2. During a median follow-up of 7.2 years (interquartile range, 3.2-13.3 years), a higher BMI was associated with reduced survival after adjusting for baseline covariates (P = .001). CONCLUSIONS: SM is safe and effective in HCM patients with obesity, but the risk of late death increased with increasing BMI. Attention to risk factor management through weight loss may improve late results after SM.

Surgical management of diastolic heart failure after septal myectomy for obstructive hypertrophic cardiomyopathy.

OBJECTIVE: Some patients with obstructive hypertrophic cardiomyopathy may remain limited after surgical relief of the subaortic obstruction. In this report, we describe experience in surgical management of patients with advanced diastolic heart failure symptoms after adequate transaortic septal myectomy for obstructive hypertrophic cardiomyopathy. METHODS: We identified adult patients who presented with heart failure symptoms after previous transaortic septal myectomy for obstructive hypertrophic cardiomyopathy and underwent repeat sternotomy for transapical myectomy to enlarge a small left ventricular cavity. Functional recovery after hospital dismissal was assessed through a questionnaire-based survey. RESULTS: Six patients with previous septal myectomy presented with New York Heart Association functional class III symptoms. Preoperative transthoracic Doppler echocardiography confirmed adequate relief of subaortic outflow tract obstruction with only trivial or mild mitral valve regurgitation; left atrial volume index was increased at 46 mL/m2 (range, 44-47 mL/m2). Following transapical myectomy, the left ventricular diameter was enlarged from 23 mm (range, 21-27 mm) to 29 mm (range, 27-31 mm) at end-systole and from 40 mm (range, 38-42 mm) to 43 mm (range, 42-50 mm) at end-diastole. All the patients were alive after a median follow-up of 0.6 years (range, 0.4-3.5 years), and 5 patients responded to a postoperative survey and indicated improvement in their heart condition compared with functional status before the repeat myectomy. CONCLUSIONS: Patients with diastolic heart failure after septal myectomy for obstructive hypertrophic cardiomyopathy may present with systolic cavity obliteration due to excessive myocardial hypertrophy. Repeat transapical myectomy can enlarge the left ventricular chamber and augment the diastolic volume, which results in improved physical capacity and patient-perceived functional status.

Longitudinal Cost of Septal Myectomy Versus Alcohol Septal Ablation for Hypertrophic Cardiomyopathy.

OBJECTIVE: To compare the postprocedural health care utilization and cost of septal myectomy (SM) and alcohol septal ablation (ASA). PATIENTS AND METHODS: Using the OptumLabs Data Warehouse, we analyzed de-identified claims data of adult patients undergoing SM and ASA for obstructive hypertrophic cardiomyopathy from January 1, 2006, through December 31, 2018. We used propensity score weighting to compare the 2-year incidence rates of emergency department visits and rehospitalizations after SM and ASA. RESULTS: We identified 953 patients in total: 660 underwent SM and 293 underwent ASA. There was no difference in the risk (odds ratio, 1.1; 95% CI, 0.6 to 1.8) or frequency (incidence rate ratio, 1.1; 95% CI, 0.8 to 1.5) of emergency department visits, but the annual risk of hospital readmission was 10.8% after SM and 25.9% after ASA during the second postoperative year (P=.004). In those who were ever readmitted, the average length of hospital stay within the first 2 years after ASA was 1.6 times as long as that after SM (incidence rate ratio, 1.6; 95% CI, 1.0 to 2.4). Overall, the 2-year cumulative postprocedural cost was significantly higher after ASA (P<.001). CONCLUSION: Compared with ASA, SM is associated with fewer hospital readmissions and lower 2-year postprocedural health care cost.